Electrosurgical generator apparatus

Abstract

An electrosurgical generator apparatus controls a variable output signal to electrodes. The generator apparatus operates in a cut mode, a coagulation mode or a stimulate mode. The generator apparatus comprises a DC power supply that provides regulated low voltage and high voltage outputs and a radio frequency (RF) waveform generator circuit that provides pulse duration modulation (PDM) of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes. A control circuit controls a variable output signal to electrodes used in electrosurgical procedures. The control circuit comprises a DC power supply circuit that provides regulated low voltage and high voltage outputs and an RF waveform generator circuit that provides pulse duration modulation of a carrier signal. The carrier signal directly affects the variable output signal to the electrodes.

1. An electrosurgical generator apparatus that controls a variable output signal to electrodes, the generator apparatus comprising:
 (a) a DC power supply that provides regulated low voltage and high voltage outputs; 
 (b) a radio frequency (RF) waveform generator circuit that provides modulation of a carrier signal, the carrier signal directly affecting the variable output signal to the electrodes; 
 (c) an impedance monitoring circuit that detects an impedance as measured across a pair of leads of the electrodes, the impedance monitoring circuit including a bridge detector for measuring an overall signal and a reference detector for measuring a reference signal, the impedance being a complex value. 
 
     
     
       2. The electrosurgical generator apparatus according to  claim 1 , wherein the bridge detector further comprises a bridge in-phase detector for measuring overall in-phase components of the overall signal and a bridge quadrature detector for measuring overall quadrature components of the overall signal. 
     
     
       3. The electrosurgical generator apparatus according to  claim 1 , wherein the reference detector further comprises a reference in-phase detector for measuring reference in-phase components of the reference signal and a reference quadrature detector for measuring reference quadrature components of the reference signal. 
     
     
       4. The electrosurgical generator apparatus according to  claim 1 , wherein the impedance is correspondingly proportional to an amount of cell destruction caused by the generator apparatus. 
     
     
       5. The electrosurgical generator apparatus according to  claim 1 , wherein the complex impedance value includes magnitude and phase angle.